Lined tanks



T. F. DOWNS June 4, 1957 LINED TANKS 2 Sheets-Sheet 1 Filed Feb. 17,1955 INVENTOR mama 500W:

ATTORNEY T. F. DOWNS LINED TANKS June 4, 1957 2 Sheets-Sheet 2 FiledFeb. 17, 1955 INVENTOR ATTORNEY United States Patent LINED TANKS ThomasF. Downs, West Chester, Pa. Application February 17, 1955, Serial No.488,811 3 Claims. (Cl. 220-63) My invention relates to a tank whichincludes a replaceable liner. Further, my invention relates to a linerassembly which may be used to protect a tank from damage by the fluidheld therein.

It is the purpose of my invention to extend the life of fluid-holdingtanks by the utilization of a flexible liner which may be easily mountedwithin a tank and removed and cleaned or disposed of after use for aperiod of time. It will be appreciated that the various deposits carriedby fluids which adhere to tanks may be easily removed and disposed ofmerely by the removal of my liner assembly.

Another advantage is the ability of my liner assembly to withstandextreme heat and other conditions such as solvent and chemical attack,moisture and exposure to rapidly changing temperatures.

My research has discovered that a film, preferably a polyester filmproduced from a material which is the reaction product of ethyleneglycol and terephthalic acid and which is known to the trade by the DuPont trademark Mylar, can be utilized for the protection of tanks bymounting the film on a continuous band-like insert which is in turnadjustably aflixed in overlying engagement with the inner face of aflange joint of a tank. By this means of attachment the capacity of thetank may be increased, if desired, and the water-tight integrity of thepolyester film and insert liner can be efiiciently maintained overextended periods of use.

Various objects and features of the invention will be fully understoodfrom the following description of a, typical form and application of theinvention throughout which descriptive reference is made to theaccompanying drawing in which:

Fig. 1 is a front elevational view in section showing the replaceableliner assembly mounted in a spherical tank;

Fig. 2 is a front elevational view of the spherical tank of Fig. 1;

Fig. 3 is a greatly enlarged view in section of a portion of the flangemounting system employed by my instant invention;

Fig. 4 is a perspective view of the replaceable liner assembly; and

Fig. 5 is a top view taken on line 55 of Fig. 2 showing the placement ofthe afi'ixing means in the flange connection.

Referring now to Fig. 1, it will be seen that the spherical tankcomprises an upper hemisphere 15 and a lower hemisphere 16, these beingconnected at their peripheral flanges 18 and 19 by suitable bolts 14.

Inside the spherical tank is positioned the replaceable liner assemblyof the instant invention which includes a continuous band-like insert 20to which is cemented an upper liner hemisphere 21 of flexible linermaterial and a lower liner hemisphere 22 of the same material.

As seen in Fig. 3, the spherical tank has been modified by the provisionof upper and lower enlarged holes 23 and 28, respectively, which receivethe bolts for maintaining the replaceable liner assembly in properposition at the flange joint. The band-like insert 20 is of a dimensionsufficient to overlap the flange joint. At the upper edge of theband-like insert 20, suitable lugs, such as nuts 24, are welded to theinner face of the insert 20 to provide threads for the upper insertattaching bolts 25. The lower edge of the insert 20 may be similarlyequipped with internally threaded lugs 25 and at least one projectingbolt 27 which may be used for stabilizing the insert 20 during assembly;this projecting bolt 27 facilitates alignment of the lower lugs 25 withthe lower tank holes 28 for insertion and attachment of the lower insertattaching bolts 29.

The liner hemispheres are preferably made of a polyester film which isproduced from a material which is the reaction product of ethyleneglycol and terephthalic acid. This film is known to the trade, aspreviously mentioned, under the trademark Mylar and it is considered thestrongest of all plastic films, exhibiting a tensile strength ofone-third that of machine steel and having an operating temperaturerange from 60 C. to C.

This film is used to produce the hemispherical portions through a vacuumtechnique which forms the film into the proper shape. The film as shownin Fig. 3 is cemented to the insert, the insert being of suitablematerial such as brass, steel or plastic.

Preferably upper and lower gaskets 30 and 31 are cemented over the linerhemispheres 21 and 22, respectively, at the upper and lower edges,respectively, of the insert 20 to present cushion-type means which arepressed against the tank hemispheres 15 and 16, respectively, when thereplaceable liner assembly is drawn into final assembled position bymeans of the bolts.

Where it is desired to utilize the replaceable liner and also expand thecapacity of the tank, the insert may be designed to enable the spacingapart of the upper and lower tank flanges 34 and 35, respectively, and,to suitably support the weight of the upper tank hemisphere 15, spacers36 may be positioned between the flanges. The enlarged holes 23 and 28through which the liner attaching bolts pass compensate for variationsin alignment and dimensions.

In large tanks it has been found advisable to employ air vents and inthe spherical tank assembly shown it is preferred that an upper vent 37and a lower vent 38 be used, these vents enabling the exhaust of trappedair between the liner and the tank as the fluid enters the tank andforces the flexible liner into complete conformance with the innersurface of the tank wall.

As seen in Figs. 3, 4 and 5, connections to the tank can be made throughthe insert, such as the connections 39 and 40 which are shown. Thespacers 36, being segmental, enable access to the insert to facilitatethe making of the necessary connections.

While the foregoing description and accompanying drawings illustrate apreferred manner of employing my invention, it should be understood thatthe invention comprehends variations and modifications differing fromthe disclosed embodiment, without departing from the scope of theinvention defined in the appended claims.

I claim:

1. A replaceable liner assembly for a sectional tank having flanges forcoupling the tank wall sections together by a flange joint, saidreplaceable liner assembly comprising a band-like insert overlapping theinner surface of said flange joint and lying adjacent the peripheralportions of the wall of the tank adjacent said joint, means foradjustably mounting said band-like insert on the tank, and flexibleliner sections aflixed to said insert and sandwiched between saidband-like insert and the tank wall sections to protect the walls of thetank.

2. A tank in accordance with claim 1 and wherein said l atented June 4,1957 flexible liner sections are made of a polyester film which is thereaction product of ethylene glycol and terephthalic acid.

3. A tank in accordance with claim 1 and wherein said means foradjustably mounting said band-like insert on the tank are positioned in.a predetermined manner to cause a predetermined separation of the tankflanges and thereby increase the capacity of the tank.

7 References Cited in the file of this patent UNITED STATES PATENTS

